Hormonal therapy is used to treat any stage of hormone-receptor-positive breast cancer or to reduce the risk of developing it or having a recurrence. Hormonal therapy can be used by both pre- and postmenopausal women. Hormonal therapy can be given before, at the same time as, or after other breast cancer treatments.

Besides treating hormone-receptor-positive breast cancers, hormonal therapy medicines also can be used to:

lower the risk of hormone-receptor-positive breast cancer coming back

lower the risk of hormone-receptor-positive breast cancer in women who are at high risk but haven't been diagnosed with breast cancer

Because there are seven different hormonal therapy medicines and because people take hormonal therapy for many different reasons, your hormonal therapy regimen will depend on your unique situation. Some of the most common situations are discussed below.

Which hormonal therapy medicine will I take?

This will depend on many factors, including:

your menopausal status

breast cancer stage

your history, if any, of blood clots

your bone density

your history, if any, of arthritis

your personal risk of uterine and ovarian cancer

any side effects you experience once you start taking a hormonal therapy

The American Society of Clinical Oncologists (ASCO) recommends hormonal therapy medicines based on cancer stage and menopausal status:

Early-stage breast cancer and postmenopausal: ASCO recommends that postmenopausal women diagnosed with early-stage, hormone-receptor-positive breast cancer consider an aromatase inhibitor as the first hormonal therapy medicine. A woman who has taken tamoxifen for 2 to 3 years may want to consider switching to an aromatase inhibitor. Aromatase inhibitors are sometimes used beyond 5 years of tamoxifen to further reduce the risk of breast cancer recurrence.

Advanced breast cancer: ASCO recommends that women diagnosed with advanced (metastatic) hormone-receptor-positive breast cancer consider taking an aromatase inhibitor after 2 to 5 years of tamoxifen, or whenever the cancer stops responding to tamoxifen. If the cancer stops responding to an aromatase inhibitor and tamoxifen, consider Faslodex (chemical name: fulvestrant).

You and your doctor will look carefully at all your hormonal therapy medicine options and decide on a treatment plan that is best for you and your unique situation. If you have side effects from taking one hormonal therapy medicine, you may be able to switch to another one.

How long do I take hormonal therapy?

How long you take hormonal therapy depends on if you're taking it before or after surgery as well as cancer stage and any side effects you may have.

In some cases, your doctor may recommend that you take a different hormonal therapy medicine after the 5 years of the first one is up. For example, if you've taken tamoxifen for 5 years, your doctor may recommend that you take an aromatase inhibitor for an additional period of time. Doctors call this extended adjuvant hormonal therapy. Researchers are studying how long the second hormonal therapy medicine should be taken after 5 years of the first one.

Postmenopausal women taking hormonal therapy BEFORE surgery for early-stage hormone-receptor-positive breast cancer may take hormonal therapy medicine for 3 to 6 months before surgery to shrink the cancer. Doctors call this neoadjuvant hormonal therapy. How long you take hormonal therapy before surgery depends on your unique situation, so your treatment plan may be very different from someone else’s. Your doctor may recommend hormonal therapy before surgery if the cancer is large.

Pre- or postmenopausal women taking hormonal therapy for advanced (metastatic) hormone-receptor-positive breast cancer usually take hormonal therapy for as long as it works. If the cancer stops responding to one hormonal therapy medicine, your doctor usually will recommend a different hormonal therapy medicine.

You and your doctor will look carefully at all your hormonal therapy medicine options and decide on a treatment plan that is best for you and your unique situation.

How do I take hormonal therapy?

All the hormonal therapy medicines EXCEPT Faslodex (chemical name: fulvestrant) are pills that are taken once a day. Most doctors recommend taking hormonal therapy at the same time each day so you remember to take the medication. Hormonal therapy medicines can be taken with or without food.

Faslodex is a liquid that is given once a month as an injection into a muscle. You usually get a Faslodex injection in your doctor's office.